Amid the Vatican Gardens, visible from the Museums' galleries leading to and from the Sistine Chapel, stands the Casina of Pius IV. The Casina was begun in 1553 by Pirro Ligorio and Sallustio Perruzzi, and completed between 1560 and 1562. This villa consists of four separate sections, with two pavilions and two arched gateways, connected by an oval inner court like an ancient nymphaeum, decorated with statues in the round, high reliefs, bas-reliefs, festoons, friezes, escutcheons and frames in stucco, where putti ride on waterspewing dolphins. It was here that Pius IV used to enjoy moments of peace and solitude. Also his nephew, St. Charles Borromeo, then Cardinal Secretary of State, held here his famous literary evenings.

Since 1926, it has been used as the seat of the Pontifical Academy of Sciences, which encompases both the Academy of the Sciences and Social Sciences. The Pontifical Academy of Sciences consists of eighty scientists (Sciences and Social Sciences) selected from around the world who are appointed for life by a sovereign act of the Pope. Candidates for a seat in the Academy are chosen by the Academy on the basis of their outstanding original scientific studies and their acknowledged moral personality, without any ethnic or religious discrimination.

The aim of the Academy is to promote the progress of the mathematical, physical and natural sciences and to advance the understanding of the history and philosophy of Science. It promotes scientific investigations and research which can contribute, in the appropriate areas, to the exploration of moral, social and spiritual problems. The findings of the international scientific conferences held at the Pontifical Academy of Sciences are given to the Holy Father for his knowledge and for use in his teachings to humanity. With the object of promoting scientific research the Academy every two years awards the Pius XI Medal to a young scientist of international reputation.

The Pontifical Academy of Sciences is the only organization of its kind in the world. Its home, the Casina of Pius IV is one of the most delightful architectural complexes in the Vatican which has just completed an intensive three-year restoration project thanks to the generosity of the Homeland Foundation, New York.